Whether to check that the input matrix contains only finite numbers.
Disabling may give a performance gain, but may result in problems
(crashes, non-termination) if the inputs do contain infinities or NaNs.

Returns :

lu : (N, N) ndarray

Matrix containing U in its upper triangle, and L in its lower triangle.
The unit diagonal elements of L are not stored.

piv : (N,) ndarray

Pivot indices representing the permutation matrix P:
row i of matrix was interchanged with row piv[i].